In a heterodyne architecture, a received signal is downconverted to an intermediate frequency (IF), rather than to baseband, for signal processing using a mixing operation. One inherent problem in heterodyne receivers is that when downconverting the received signal to the desired intermediate frequency, an image of the received signal is also converted to the desired intermediate frequency as a result of the mixing operation. More specifically, because the mixing operation does not preserve the polarity of the difference between its two input frequencies, the receive frequency and the image frequency, which are located at an equal distance from either side of a local oscillator (LO) frequency used in the mixing operation, are translated to the same IF frequency. Since power of the image signal may not be regulated and can be much higher than that of the desired signal, image rejection must be performed.
In order to provide image rejection, many heterodyne receivers utilize a quadrature architecture. More specifically, the received signal is downconverted to the desired intermediate frequency using a quadrature mixing operation. However, achievable image rejection of such quadrature architectures is limited by the amount of I/Q mismatch in the receiver. As such, there is a need for a system and method of correcting I/Q mismatch in a heterodyne receiver in order to improve image rejection.